Prostate problems, such as benign prostate hyperplasia (BPH) and malignant prostate cancer, are common occurrences among older men. The effects of these diseases are generally accompanied by swelling or enlargement of the prostate gland. Apart from the life-threatening aspects of malignant prostate cancer, the everyday symptoms and effects of these diseases are usually troublesome. One such problem relates to the ability to control and achieve normal urine discharge. When the prostate gland enlarges to the extent that it obstructs the prostatic urethra through the prostate gland, considerable difficulties arise in discharging urine at will. Such difficulties are typically referred to as urinary tract retention. Urinary tract retention can be either acute or chronic.
Surgical treatments are available for relieving urinary tract retention caused by an obstruction of the prostatic urethra. One such treatment is a transurethral resection of the prostate (TURP). A TURP procedure involves surgically resecting tissue from the prostate gland to eliminate or reduce the obstruction or restriction. Surgical operations offer a high probability of an excellent clinical outcome, but they are associated with a high degree of morbidity. Alternative treatments with milder side-effects include transurethral microwave thermotherapy (TUMT), radio frequency needle ablation (TUNA), interstitial laser and hot water induced thermotherapy (WIT). All of these alternative treatments involve heating the obstructive prostatic tissue until the tissue is destroyed or damaged. Thereafter, the destroyed or damaged tissue sloughs off, is absorbed in the body, and otherwise results in an enlargement of the urinary passageway through the prostate gland. The enlargement of the urinary passageway through the prostate gland eliminates or relieves the obstruction and permits better urine flow.
Another form of urinary tract retention results from a weak bladder. A weak bladder condition results when the muscle that surrounds the bladder does not contract and compress the bladder sufficiently to create enough fluid pressure on the urine within the bladder to dilate the orifice in the external urinary sphincter muscle in males and establish a substantial flow of urine into a urinary canal which leads to the exterior of the body. Males have two urinary sphincter muscles: an internal urinary sphincter muscle at the bladder neck or junction of the urethra with the bladder, and an external urinary sphincter muscle at the downstream point where the prostatic portion of the urethra exits from the prostate gland into the urinary canal through the penis.
Under normal conditions when urine is not discharged, both urinary sphincter muscles are constricted to close their orifices and prevent the flow of urine through the urethra. The muscle surrounding the bladder relaxes while the bladder is naturally filled with urine. To urinate, the muscle surrounding the bladder contracts automatically to create fluid pressure on the urine within the bladder. Pressure from the urine is applied to the constricted internal urinary sphincter muscle and is sensed by the brain. The orifice through the internal urinary sphincter muscle is voluntarily dilated to pass urine from the bladder into the prostatic urethra. However, if the muscle surrounding the bladder does not apply sufficient pressure on the urine, there is insufficient fluid pressure on the normally-constricted external urinary sphincter muscle to cause it to dilate or open. The external urinary sphincter muscle opens in response to the fluid pressure conducted through the prostatic urethra. Under circumstances of insufficient fluid pressure, the external urinary sphincter muscle will not dilate or will dilate only slightly, thereby restricting or preventing urine discharge. The inability to empty the bladder of urine can lead to serious health problems and death.
In those cases where the diseased prostate gland cannot be treated by a TURP or by a heat treatment, and in those cases where a weak bladder prevents or restricts urine flow, it is necessary for a mechanical fluid passageway to be established from the bladder. The most prevalent mechanical way to open the external urinary sphincter muscle is to insert a full-length catheter. The full-length urinary catheter extends from the exterior opening of the penis through the entire length of the urinary tract into the bladder. The full-length catheter forms a tubular stent which permanently holds the urinary sphincter muscle open, thereby preventing it from closing and restricting the flow of urine. In some cases, the patient is taught to insert a full-length catheter whenever urination is necessary. In other cases, where the patient cannot insert the full-length catheter himself, medical personnel insert an indwelling full-length catheter in the urinary tract where it must remain. In some cases, the full-length catheter must be used for the remainder of the individual's life.
TURP and the prostate heat treating techniques cause temporary side effects, for example inflammation and swelling of the prostate. The swelling may be so great as to obstruct the passage of urine through the surgically-treated prostate gland. Direct contact from urine can aggravate the inflammation and increase the risk of infection to the viable but nevertheless raw, tender and swollen tissue of the prostate gland after a TUMT or a heat treatment. These side effects of a TUMT or heat treatment usually require the patient to use an indwelling urine drainage catheter for a few days up to several weeks following the procedure to permit urination while the swelling subsides and the tissue of the prostate gland heals or stabilizes.
Because a full-length urinary drainage catheter provides a continuously open interior urine flow passageway between the bladder and the exterior opening of the penis, a clamp or other mechanical valve must be used at the exterior of the body to control the urine flow from the catheter. The clamp or valve is opened to drain the urine from the bladder and is closed to terminate urine flow from the bladder. Alternatively, a reservoir may be attached to the end of the catheter to collect the discharged urine, in which case the mechanical valve or clamp may not be used.
The extension of the catheter out of the exterior opening of the penis, the presence of the clamp or valve and the presence of the reservoir cause discomfort, are awkward to deal with and may be embarrassing. The full-length urinary catheter may create limitations from a social standpoint and almost always creates quality of life issues which must be confronted. Sexual activity is impossible. An increased risk of infection also results.
Because of the quality of life and social issues associated with full-length urinary catheters, partial-length indwelling catheters have been developed. Partial-length indwelling catheters typically extend from the bladder partially along the prostatic urethra, but not along the entire length of the urinary tract from the bladder to the exterior opening of the penis. The typical partial-length indwelling catheter extends from the bladder through the prostatic urethra to an upstream position adjacent to the external urinary sphincter muscle. The reduced length permits the external urinary sphincter muscle to control urine flow in a more natural manner, while still bypassing most of the urine flow around the swollen, obstructed or raw prostate gland.
Keeping a partial-length indwelling catheter in the proper position is essential. The short length may allow the catheter to move completely into the bladder or move out of the bladder into the urethra and the urinary canal. Either type of unintended movement may require serious medical intervention to correct.
A partial-length urinary catheter typically uses an inflatable balloon or other form of anchor at its end which is within the bladder. The balloon or anchor is expanded or enlarged within the bladder. The expanded or enlarged balloon or anchor contacts the bladder neck at the entrance to the urethra and prevents the partial-length catheter from moving out of the bladder and into the urethra. Another downstream anchor is typically attached to the partial-length of catheter to prevent the catheter from moving in the opposite direction into the bladder. The downstream anchor is positioned downstream from the external urinary sphincter muscle and is connected to the partial-length catheter with a short length of thread-like material. The thread-like material extends through the orifice of the external urinary sphincter muscle between the downstream anchor and the partial-length indwelling catheter. The catheter and the downstream anchor are therefore positioned on opposite sides of the external urinary sphincter muscle. The normal constricted state of the external urinary sphincter muscle restrains the downstream anchor and prevents the partial-length catheter from moving into the bladder.
The external urinary sphincter muscle is able to constrict around the thread-like material to stop urine flow and is able to dilate to permit the flow of urine. In this matter, the natural functions of the external urinary sphincter muscle control the discharge of urine. The clamps, valves and reservoirs used with a full length catheter, as well as the self-consciousness, embarrassment and social problems and difficulties caused by these devices, are avoided entirely by using a partial-length indwelling catheter.
Despite the advantages and benefits of a partial-length indwelling catheter, a partial-length indwelling catheter is not effective to overcome the urine discharge problems caused by a weak bladder. The partial-length indwelling catheter terminates upstream of the external urinary sphincter muscle. Although the fluid pressure within the bladder is communicated through the partial-length indwelling catheter to the external urinary sphincter muscle, the relatively low fluid pressure from the weak bladder is insufficient to cause the external urinary sphincter muscle to open. It is for this reason that a partial-length indwelling catheter is not effective in permitting control over urine drainage under weak bladder conditions. A full-length urinary drainage catheter is required for urine drainage under weak bladder conditions and under conditions caused by some neurogenic disorders.
A partial-length indwelling catheter may also be of limited prophylactic value after a TUMT or heat treatment. The downstream end of the partial-length indwelling catheter may not immediately adjoin the external urinary sphincter muscle, but instead, because of differences in physiological length of the prostatic urethra in different males, may terminate a short distance before the external urinary sphincter muscle. This small gap between the downstream end and the external urinary sphincter muscle may swell to the point where it restricts urine flow through the prostate gland after a TUMT or other heat treatment. Similarly, the enlargement of the prostate gland due to BPH or other disease may also extend into the gap between the downstream end of the partial-length indwelling catheter and the external urinary sphincter muscle. Under such obstructive circumstances, the partial-length indwelling catheter is not effective in permitting urine discharge, thereby requiring a full-length urinary drainage catheter to be used instead of the more desirable partial-length indwelling catheter.